Hinge mechanism for the covers of loose-leaf books.



F. L. IMPEY.

HINGE MECHANISM FOR THE COVERS 0F LOOSE LEAF BOOKS.

APPLICATION FILED MAY 31, 1911.

- 1,003,265. Patented Sept. 12,1911.

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M/ITA/ESES'ES COLUMBIA PLANOURAPH 60.. WASQINGTON, D. c

FRANCIS LEVITT IMPEY, OF BIRMINGHAM, ENGLAND.

HINGE MECHANISM FOR THE COVERS 015 LOOSE-LEAF BOOKS.

Specification of Letters Patent.

Application filed May 31, 1911.

Patented Sept. 12, 1911.

Serial No. 630,334.

To all whom it may concern:

Be it known that I, FRANCIS LEVITT IMPEY, subject of the King of Great Britain, residing at 19 Barwick street, in the city of Birmingham, England, manufacturer, have invented certain new and useful Improvements Relating to Hinge Mechanisms for the Covers of Loose-Leaf Books, of which the following is a specification.

This invention relates to hinge mechanisms for loose leaf books or binders of the type in which the covers are pivotally connected at their rear edges to clamping bars by which the leaves are bound in position, the covers being connected together by leather thongs or the like which pass through the clamping or binding bars and are tightened or released for securing or liberating the leaves by mechanism arranged within one or both of the covers.

In order that such a book may open and close without appreciably varying the tension on the thongs and also to prevent any interference by the thongs with the proper opening or closing of the book, it is customary to arrange for the thongs to pass as nearly as possible through the axis or axes of the hinge or hinges. In a book of the type above described this necessitates the arranging of each cover so that it can rotate about a line which coincides with the center of the thongs at the part where the latter pass through the adjacent clamping bar, and in consequence with covers of moderate thickness when the covers are fully opened out and the thongs are straight the inner edges of the clamping bars project beyond the inner surfaces of the covers. Such a condition of the bars is objectionable inasmuch as it gives rise to an inconvenient curvature or arching of the leaves near their inner edges (or in other words it prevents the leaves from lying flat) when the book is open. Also it is found in practice that it is impossible to avoid an inconvenient variation of tension in the thongs with such hinges when the books are opened and closed.

To enable the leaves to be as nearly flat as possible, it is necessary that the inner edges of the clamping bars should lie level with or below the inner surfaces of the covers when the book is open, but this disposition is impracticable with an ordinary hinge, except by the use of excessively thick covers.

One of the objects of the present invention is to provide a simple hinge mechanism which enables the book to be opened and closed without appreciable variation of the binding pressure imposed by the bars on the inner edges of the leaves, and which also enables covers of moderate thickness to be employed and the above described disposition of the clamping bars to be obtained.

The invention comprises the formation of each hinge from a pair of links or their equivalent pivoted at their opposite ends to a cover and a clamping bar or equivalent parts, and so arranged that the opening and closing movements of the covers will not appreciably or inconveniently affect the tension of the binding thongs and the latter will therefore not obstruct the said opening and closing movements,

Referring to the accompanying sheet of explanatory drawings :Figure 1 is a side elevation and Fig. 2 a plan of a loose leaf book having this invention applied thereto. Figs. 3, 4 and 5 are diagrams illustrating the mechanism and operation of hinges constructed in accordance with this invention. Fig. 6 is a side elevation and Fig. 7 a plan to a larger scale of one of the hinge mechanisms employed with the book shown in Figs. 1 and 2.

The same reference letters in the different views indicate the same parts.

In carrying the invention into effect as shown each of the links a and Z) is made from wire shaped in the form of a rectangular loop the length of the link a being between one third and one half of the other link I); the width of the link a is also made rather less than that of the link I) so that it may pass between its sides. This is clearly shown at Fig. 7. The ends pivoted to the clamping bar 0 are arranged alongside each other at the same or at slightly different distances from or above the outer surface of the bar and with a distance between them of about twice the length of the shorter link. The ends pivoted to the cover are so situated that when the book is closed and placed horizontally the end of the link a lies above the end of the link b. In the drawings the distance between the ends attached to the cover is rather less than one third of that between the ends attached to the bar, but it may be varied considerably. For effecting the hinge connection of the links to the bar and cover any convenient means may be used, as for example, metal strips bent to embrace the ends of the links and adapted to be secured by rivets, screws or other convenient fastenings. Strips .03 provide the connection with the clamping bars 0 and strips 6 provide the connection with the covers f. The disposition of each thong g is such that, when viewed edgewise it passes between the ends of the links attached to the cover and also between the ends attached to the binding bar.

A. hinge mechanism as above described possesses the characteristic that when viewed edgewise its instantaneous axis is intersected by or coincides sufliciently for all practical purposes with an imaginary center line in the edge of the thong in all positions in the are through which the cover is ordinarily moved relatively to its adjacent clamping bar, and that the position of the instantaneous axis does, not move appreciably with respect to the said center line of the thong, so that the tension of the thong has no moment about the instantaneous center in any working position of the mechanism and the covers open and close freely without affecting, for practical purpose, the original tension on the thongs.

The action of the mechanism is clearly shown by the diagrams at Figs. 8, t'and 5.

Fig. 3 shows by lines the relative dispositions of the hinge links and thong when the book is closed. Fig. 4 shows thedisposition when the book is partly opened and Fig. 5 the disposition when the book is fully opened or the cover moved through 90 degrees with respect to the clamping bar.

The relative proportions of the links and their dispositions are capable of being varied, and in all cases it is desirable, although not essential, that the arrangement of the clamping bars be such that they do not project beyond the inner surfaces of the covers when the book is opened. The best condition as regards the disposition of the links appears to be as shown in the drawings. It will be observed that the covers and bars do not lie in the same plane when the book is closed. This is to accommodate the slightly greater thickness of the leaves at the parts where they are not gripped by the clamping bars.

In practice two or more hinges as herein described are employed on each cover and bar and the thongs are disposed between the hinges.

Instead of wire loops any other convenient construction of the links may be used.

Any convenient means are provided on the ters. Patent is copies of this patent may be obtained for five cents each, by addressing the Commissioner of latentsf 1. In hinge mechanism for loose leaf books or binders, the combination with a cover and clamping bar, and a binding thong, of a pair of links pivoted at their opposite ends to the said cover and bar and arranged so that the instantaneous axis coincides with an imaginary center line in the thong in all positions through which the mechanism is ordinarily narily moved, substantially as described.

3. In hinge mechanism for loose leaf books or binders, the combination with a cover and clamping bar and a binding thong, of a pair of links of unequal length, the length of one link being between two and three times the length of the other, the said links being pivoted at their opposite ends to the said cover and bar and arranged so that the instantaneous axis coincides with an imaginary center line in the thong in all positions through which the mechanism is ordinarily moved, substantially as described.

4. In hinge mechanism for loose leaf books or binders, the combination with a cover and clamping bar and a binding thong, of a pair .of loop like links one of which is situated within the other and both are pivoted at their opposite ends to the cover and bar and arranged so that the instantaneous axis coincides with an imaginary center line in the thong in all positions through which the mechanism is ordinarily moved,substantially as described.

5. In hinge mechanism for loose leaf books or binders, the combination with a cover and clamping bar, and a binding thong, of a pair of loop like links of unequal length 'and width, one, link being between two and three times the length of the other and the shorter one situated within the longer one,

and metal clips hingedly connecting the links to the bar and cover, the arrangement of the links being such that their instantaneous axis coincides with an imaginary center line in the thong in all positions through which the mechanism is ordinarily moved, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

FRANCIS LEVITT IMPEY.

Witnesses:

J OHN MORGAN, FRANCIS MALPAS.

Washington, D. G. 

